Affiliation:
1. Department of Clinical Viro-Immunology, Central Laboratory of the Netherlands Red Cross Blood Transfusion Service, Amsterdam, The Netherlands.
Abstract
Activation of unprimed CD4+CD45RA+/RO- T-cells results in a gradual loss of CD45RA expression concomitant with the acquisition of CD45RO. It has been suggested that this conversion occurs in vivo through a CD45RAbright/RObright stage. Next to this small CD45RAbright/RObright subset (Dbright), a larger subpopulation that expresses both RA and RO isoforms at low levels (Ddull) can be found in the circulating CD4+ T-cell population of all donors. The properties of the latter population are largely undefined. Here, we show that Ddull cells have an intermediate phenotype for antigens such as CD31, CD621, CD58, and CD95 that are differentially expressed on unprimed versus primed T cells. In addition, they are able to provide help for B-cell differentiation and contain substantial numbers of tetanus toxoid (TT)-specific precursor cells. Remarkably, both intracellular cytokine staining and analysis of T-cell clones showed that Ddull cells and CD45RO+ T-cells produce comparable high amounts of both interferon (IFN)-gamma and interleukin (IL)-4, which clearly distinguishes them from CD45RA+ and Dbright T-cells. Finally, prolonged culture of sorted Ddull cells in a mixture of IL-2, IL-6, and tumor necrosis factor (TNF)-alpha showed that about half of the population retained the Ddull phenotype. Part of the cells upregulated the CD45RA isoform, whereas only a minority switched to single CD45RO expression. Our findings indicate that the Ddull population contains primed T cells, some of which may reacquire an “unprimed” phenotype in the absence of antigenic stimulation.
Publisher
American Society of Hematology
Subject
Cell Biology,Hematology,Immunology,Biochemistry
Cited by
92 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献